Re: [PATCH v2 09/14] dt-bindings: pinctrl: realtek: Rename 'realtek,duty-cycle' to 'realtek,pulse-width-adjust'

[Krzysztof Kozlowski <krzk@kernel.org>]

On 09/03/2026 10:18, Yu-Chun Lin [林祐君] wrote:
>> On Fri, Mar 06, 2026 at 03:52:39PM +0800, Yu-Chun Lin wrote:
>>> From: Tzuyi Chang <tychang@realtek.com>
>>>
>>> Rename 'realtek,duty-cycle' to 'realtek,pulse-width-adjust'.
>>>
>>> The previous name was misleading because this hardware block is not a
>>> PWM generator. It does not generate a signal with a specific frequency
>>> and duty ratio.
>>>
>>> Instead, it provides a fixed nanosecond-level adjustment to the
>>> rising/ falling edges of an existing signal.
>>>
>>> Signed-off-by: Tzuyi Chang <tychang@realtek.com>
>>> Co-developed-by: Yu-Chun Lin <eleanor.lin@realtek.com>
>>> Signed-off-by: Yu-Chun Lin <eleanor.lin@realtek.com>
>>> ---
>>>  .../bindings/pinctrl/realtek,rtd1315e-pinctrl.yaml       | 9 ++++++---
>>>  .../bindings/pinctrl/realtek,rtd1319d-pinctrl.yaml       | 9 ++++++---
>>>  .../bindings/pinctrl/realtek,rtd1619b-pinctrl.yaml       | 9 ++++++---
>>>  3 files changed, 18 insertions(+), 9 deletions(-)
>>>
>>> diff --git
>>> a/Documentation/devicetree/bindings/pinctrl/realtek,rtd1315e-pinctrl.y
>>> aml
>>> b/Documentation/devicetree/bindings/pinctrl/realtek,rtd1315e-pinctrl.y
>>> aml index 90bd49d87d2e..7b3888b2cea8 100644
>>> ---
>>> a/Documentation/devicetree/bindings/pinctrl/realtek,rtd1315e-pinctrl.y
>>> aml
>>> +++ b/Documentation/devicetree/bindings/pinctrl/realtek,rtd1315e-pinct
>>> +++ rl.yaml
>>> @@ -133,10 +133,13 @@ patternProperties:
>>>          minimum: 0
>>>          maximum: 7
>>>
>>> -      realtek,duty-cycle:
>>> +      realtek,pulse-width-adjust:
>>
>> No, that's ABI break without explanation. "misleading" is not the sufficient
>> argument for breaking ABI.
>> You are stuck with the ABI you added back in 2023.
>>
>> Best regards,
>> Krzysztof
> 
> The reason I renamed 'realtek,duty-cycle' to 'realtek,pulse-width-adjust' is that
> during the v1 review, it was pointed out that the name caused confusion with
> standard PWM bindings [1]. Since I need to modify the driver logic to address
> this, I intended to update the binding simultaneously.

Again, confusion is not reason to break ABI.

> 
> Although the binding was added in 2023, there are currently no DTS files in the
> mainline kernel that use the 1315e, 1319d, or 1619b pinctrl device nodes.

Still ABI.

> Therefore, changing this property name will not break any existing device support
> in the mainline tree.

Yeah, but will break all other users.

Best regards,
Krzysztof